update doc for vertex arrays

since we store the colors in the vertex array, we need to mark the
mesh as changed when we change the colors

use GL_NORMAL_RESIZE instead of GL_NORMALIZE: it's faster

- added experimental support for vertex arrays in the mesh drawing code
(only for triangles at the moment). This speeds up the drawing of large
meshes tremendously!

- removed support for mesh display lists

- fixed + documented 2d elliptic algorithm
- renamed transfinite files

Added 27th node for 2nd order hexahedra

added documentation for 2nd order elements + renamed some Draw_Mesh_XXX
functions

move the compareEdgePtr function in Edge.cpp

- added some progress info during the 2nd order mesh generation (so that
  the interface does not freeze for too long)

- cosmetic changes to some other progress messages

Added final bit for 2nd order elements: the middle face nodes for
quadrangular faces (i.e., for quadrangles, hexahedra, prisms and
pyramids).

fix test in copy_mesh(surf, surf)

document edge ordering for hexa, prism and pyramid

- removed the quads from the simplex trees (finally...)

  **warning**

  this is a pretty big patch that touches a lot of different files. I
  tried my best to update all the things that needed to be updated,
  but I probably forgot some things... Please test! (especially the
  export routines in obscure formats like SMS, Gref, etc., as well as
  the extrusion code)

- added second order edge vertices for hexas, prisms and pyramids
  (drawing not done yet)

- added sanity check for number of values in post-pro parsed file
  format

- merged all mesh printing/reading routines in Print_Mesh.cpp and
  Read_Mesh.cpp

- cleaned up the statistics code

make parser

Small changes inspired by Wednesday's discussions:

- added FL::check in redraw_opengl() (and thus removed DrawUI()):
  this should (?) fix the missing redraws

- protected the orientation calculation with a lock

- made the mode selection widget do its callback even if we don't
  change the selection (so that we always go back to the top-level
  menu)

Small changes inspired by Wednesday's discussions:

- Mac only: Gmsh now publishes its "file types"... That means that
  geo/msh/pos files now have nice icons, and that you can double-click
  on a geo/msh/pos file in the Finder to open it :-)

- removed support for fltk 1.0 (wasn't compiling anymore anyway)

- doubled the timout in GmshServer (2->4s): this seems to help on
  Windows (thanks to jkools@veeco.com)

- added warnings in the docs about the Attractor feature

- increased WB by 1 pixel in the GUI

- replaced more Msg(FATAL) with Msg(ERROR) where it makes sense

missed these bits in my commit yesterday

refined the messages a little bit more, so that only valid choices are
displayed at any time. (This is wicked cool, man :-)

PS: this is probably my last commit for quite a while (in case you
wondered: I have to do a demo of gmsh tomorrow, hence all my work
the last couple of weeks...)

rewrote the contour extraction routines from scratch: one can now
select the entities in arbitrary order, and undo all the steps
interactively.

add missing list_rest in select surface/volume

add sanity check in List_Pop

- merged ONSCREEN1 and ONSCREEN2 to minimize redraws

- fixed s->Orientations test

fine-tune transformation message

- fixed race condition in surface drawing
- plugged s->Orientations memory leak
- improved "select hole" message

display the interactive messages in the graphic window (instead of the
status bar)

- added "undo" capability in geometry creation interfaces

- removed all ugly statics in Geo.cpp

- fixed a couple of bugs (recompute min/max and surf->orientations)
  after we apply geometrical transformations

adapt verbosity test to new default

removed unused routine

removed unused geom.overlay option

fixed small bug in SelectEntity (that's an old one: the init of the
entity pointers should be inside the while()...)

removed unused geom.highlight option + small cleanup of the selection code